This invention relates to agricultural balers for forming round bales of crop material and automatically wrapping the bales with twine before releasing them onto a field. More particularly, the invention relates to improvements in the twine wrapper control system to enable control system operation using a simplified operator console.
Demand for operational efficiency continues to increase in crop packaging, especially in round balers. Efficiency gains in equipment operation and/or improvements in equipment operating lifespan all serve to improve the economics surrounding crop packaging. Improvements are typically introduced in larger balers where tractors are equipped with sophisticated control systems that can interface with increasingly complex implement control systems to achieve the desired implement operational efficiency improvements. It is also desirable to offer the equipment operational improvements across an entire equipment line, not just the larger, more complex models. Adapting the sophisticated control systems necessary to achieve the operational improvements to simpler implements and/or tractors that may lack some or all of the necessary control system features demands innovation.
One such improvement is an automatic bale wrapping system for round balers. Typical round balers having automatic wrapping capability, such as those produced by Case New Holland North America, pick up crop material from a field and form it into a compacted round bale in a bale forming chamber. When the bale has been compacted to a desired density (or reached a desired size), bale density (or size) sensors send signals to a controller which in turn sends signals to an operator's panel to alert the operator to stop forward motion of the baler so that the bale may be wrapped with netting or twine according to a program of instructions stored in the controller memory.
After a brief delay allowing time for the operator to stop forward motion of the baler, the controller initiates a wrap cycle. The mechanism for wrapping with twine includes one or more hollow twine tubes. Strands of twine are fed from twine rolls through the tubes. When a wrap cycle is initiated, the twine tubes are moved arcuately to an extended or insert position with an end of each twine strand dangling from the end of a respective one of the tubes. A pusher mechanism, usually referred to as a “duckbill”, is actuated to move the dangling ends toward the bale so that the ends of the twine strands are adjacent the bale near its lengthwise middle. The strands are caught up in the bale which is rotating within the bale forming chamber. The bale is then wrapped in a pattern by moving the twine tubes toward a home (outboard) position with programmed pauses at intervals to place circular wraps on the bale. The twine is cut after end wraps have been placed on the bale and the bale is ejected from the baler onto the ground. The mechanism for wrapping with net relies on fingers in the duckbill to hold a free end of the net wrap and insert the free end into the bale forming chamber. Once the net wrapper is engaged by the bale, the duckbill is partially withdrawn until the bale is fully wrapped. The duckbill is then fully withdrawn once the bale is fully wrapped which severs the net wrap from the supply allowing the wrapped bale to be ejected from the baler. Twine tubes are not required with a net wrap system. Another signal from the controller to the operator interface informs the operator that forward motion for crop pickup can resume once the wrapping process is completed. A display console communicating with the control system informs the operator of the wrapping progress, alerts the operator to any problems in the wrapping cycle, and often provides touch-sensitive controls for operator input options.
While such operator convenience is readily accomplished on tractors having electronic control systems, data communications networks, and video screen operator displays already installed, it would be similarly advantageous to provide a similar level of bale wrapping automation on less complex tractors. With this in mind, it would be advantageous to provide a control system for automating the bale wrapping process which includes an ECU and a simplified operator interface capable of functioning without a visual display or similarly complex tractor-mounted operator interface. Further advantages would be realized by a simplified operator interface capable of providing alarm and monitoring capability for the entire baler operation process and operator control inputs for adjusting key parameters, calibrating sensors, and manual bale wrapping initiation. These and other advantages are provided by the draft control system described below.